The MATRICS Consensus Cognitive Battery (MCCB) is a gold-standard tool for assessing cognitive functioning in individuals with severe mental illness. This study is an initial examination of the validity of remote administration of 4 MCCB tests measuring processing speed (Trail Making Test: Part A, Animal Fluency), working memory (Letter-Number Span), and verbal learning and memory (Hopkins Verbal Learning Test-Revised). We conducted analyses on individuals with bipolar disorder (BD) and schizophrenia-spectrum disorders (SCZ), as well as healthy volunteers, who were assessed in-person (BD = 80, SCZ = 116, HV = 14) vs. remotely (BD = 93, SCZ = 43, HV = 30) to determine if there were significant differences in performance based on administration format. Additional analyses tested whether remote and in-person assessment performance was similarly correlated with symptom severity, cognitive and social cognitive performance, and functional outcomes. Individuals with BD performed significantly better than those with SCZ on all MCCB subtests across administration format. Animal Fluency did not differ by administration format, but remote participants performed significantly worse on Trail Making and HVLT-R. On the Letter-Number Span task, individuals with bipolar disorder performed significantly better when participating remotely. Finally, patterns of correlations with related constructs were largely similar between administration formats. Thus, results suggest that remote administration of some of the MCCB subtests may be a valid alternative to in-person testing, but more research is necessary to determine why some tasks were affected by administration format.